Translation:The companies are located in Canada.
The German sentence doesn't single out "offices." It simply states that the companies are located in Canada, not just that their offices are in Canada, while some other parts of the company, manufacturing plants or whatever, might be in some other country. So "The companies have their offices in Canada" is not a faithful translation.
Note also that the literal translation is "The companies have their location in Canada." But that's the sort of unnecessarily awkward/verbose/not quite native English (influenced by the German) that Duolingo doesn't want to encourage. German may say it that way, but English doesn't. The companies don't have their location in Canada; they are located in Canada.
I think "The companies have their location in Canada" is perfectly fine and should be accepted. DL seems to have mood swings between "Translate that more colloquially" and "Translate that in a way more faithful to the original". One just has to gamble which way the little green owl is feeling at the moment.